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Old 25th Jan 2023, 11:46 pm   #41
Katar83
Pentode
 
Join Date: Feb 2021
Location: Thetford, Norfolk, UK.
Posts: 133
Default Re: What did I get myself into? Murphy A40C.

Well, that sucks, cobbled up some capacitors in series to replace the dead 8uf cap, plugged in new UU5 valve, powered it all up and everything started glowing nicely but not a sound from speaker.
Switched to LW and I could just about hear static from somewhere inside the tunning capacitor, eventually even tuned in to something but couldn't tell what as was too quiet. Checked everything, still not a sound from speaker. Was about to give up for the evening but as last thing checked the speaker itself and of course its dead, no idea why I haven't checked it first
Plugged in temporarily my spare wharfedale 8 ohm speaker and of course it all works, BBC on LW is the only station I could tune to, AM just lots of static, SW too although I havent figured out how this actually works. I've used a piece of wire connected to actual antenna.
Both cords snapped quickly so repaired them temporarily with some dental floss

So two questions for now, what dial cord size should be in there, original looks closer to 0.6mm to me but its so old and degraded that it may as well been 1mm before the war.
What speaker should I look for, I take it, it should be a 15 ohm speaker. Looks like there's some 10-12" Wharfedale 15 ohm speakers on eBay right now from similar era. Would that be a good choice for a replacement?
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